He challenged them to have a believing heart in order to have a successful career with the Department of Foreign Affairs.
"Believe in God, believe in yourself and believe in those who believe in you in order to be a successful public servant," Dihm told the graduates.
A total of 28 graduands have finished the 12 modules in 12 months.
The training was an initiative of the PNG Foreign Affairs and the New Zealand Foreign Affairs and Trade ministry.
The vision of the training program is to re-establish a quality standard of PNG foreign service officers.